Diono Monterey 2XT

The Monterey 2XT is a balanced performer for ease-of-use and belt fit in highback mode. Because of the wide discrepancy in belt fit between the highback and backless modes, we recommend keeping the Monterey 2XT as a highback booster for better belt fit. It’s a very wide booster that may overlap vehicle belt hardware and contact interior trim or the head restraints in adjacent seats—a space consideration for families who need to fit 2 or more car seats across the rear seat. The Monterey 2XT offers height adjustment as well as side width adjustment, but the knob is stiff to use.

CR recommends highback boosters for everyday use because they typically position the shoulder belt better on a child, provide some side-impact protection, and offer a more comfortable place for resting children to lay their head. Once your child outgrows their forward-facing child car seat by weight or height, CR and the American Academy of Pediatrics (AAP) recommend that kids use boosters until they are at least 4 feet 9 inches tall, are 8 to 12 years old, and have the developmental maturity to keep their belt properly positioned for an entire car ride.

The Diono Monterey 2XT is part of the Car Seats test program at Consumer Reports. In our lab tests, Booster Seats models like the Monterey 2XT are rated on multiple criteria, such as those listed below.

Booster fit (with back): A rating that reflects a booster seat's ability to correctly position the lap and shoulder belts in various test vehicles using a child-sized dummy, when used as a highback booster. Additionally, it includes an assessment of the booster's compatibility with vehicle seats and interior components.

Booster fit (no-back): A rating that reflects a booster seat's ability to correctly position the lap and shoulder belts in various test vehicles using a child-sized dummy, when used as a backless booster. Additionally, it includes an assessment of the booster's compatibility with vehicle seats and interior components.

Ease of use: Our evaluation of how easy each seat is to use, including items such as the clarity of labels and instructions, the ease of achieving an appropriate belt fit, and the transition between highback and backless modes where applicable.